This invention relates to a propulsion unit of a vehicle and more particularly, to a vehicle propulsion unit whose engine, which is driven by combustion of fuel, is provided with a dynamotor which is driven by electrical energy and functions as a generator.
In vehicles, there is a so-called hybrid vehicle whose engine, which is driven by combustion of fuel, is provided with a dynamotor which is driven by electrical energy and functions as a generator (a motor). The dynamotor includes a motor rotor, which turns with a crankshaft of the engine, and a motor stator (coil), which is disposed for correspondence to the motor rotor.
This hybrid vehicle is provided with an engine control means and a motor control means, which respectively control the operating state of the engine and the dynamotor. While driving, the engine control means and the motor control means detect the operating state of the engine and the dynamotor, as well as control the operating state of the engine and the dynamotor depending upon a running state of the vehicle. This enables the hybrid vehicle to achieve a high level of engine performance in terms of fuel consumption, harmful exhaust component value, and engine power.
In addition, this hybrid vehicle is provided with a rotational displacement detection mechanism (a sensor), which detects rotational displacement of the motor rotor to the motor stator.
The rotational displacement detection mechanism includes a sensor rotor which turns with the crankshaft and a stator which corresponds to the sensor rotor (coil).
Several examples of such a construction of a dynamotor and a motor are disclosed in e.g., Patent Laid-Open No. Hei 11-78558 bulletin, Patent Laid-Open No. Hei 9-19104 bulletin, Patent Laid-Open No. Hei 7-170688 bulletin, and Patent Laid-Open No. Showa 63-198556 bulletin.
According to the above Patent Laid-Open No. Hei 11-78558 bulletin, a shielding member is disposed between an engine and a dynamotor, and a partition, which functions as a shielding member, is provided between the dynamotor and a flywheel.
According to the above Patent Laid-Open No. Hei 9-19104 bulletin, in an electric wheel motor, measures are taken to maintain signal lines water-proof and dust-tight.
According to the above Patent Laid-Open No. Hei 7-170688 bulletin, in a spindle motor, two openings or pores are formed for whirl-stopping of a disc in a rotor hub.
According to the above Patent Laid-Open No. Showa 63-198556 bulletin, a cooling water passage is formed so as to direct cooling water to cool an armature coil and a field coil.
However, the dynamotor such as that disclosed in the above Patent Laid-Open. No. Hei 11-78558 bulletin involves inconveniences. There is only a narrow slit between a position detection sensor, which functions as a rotational displacement detection mechanism, and a stator. Therefore, magnetic flux and radio wave noise, which leak from the stator of the dynamotor, negatively influence the position detection sensor. As a result, noise occurs in the signal of the position detection sensor.
In addition, although a rotor and a flywheel are disposed by means of a location pin, there are no means to determine where to dispose the detection sensor and a drive plate in which a pore is formed. This brings about an inconvenience of precisely aligning the position of the detection sensor and the drive plate.
Further, although the rotor is provided with a fin which cools the dynamotor, because it is air-cooling, this brings about a further inconvenience of low cooling efficiency.
Furthermore, additional components include a housing and a connector. Further, an offtake of a terminal from the dynamotor is formed of many parts, including a connection ring, a terminal portion, and a terminal board. For that reason, the structure becomes complicated and expensive.
In order to obviate or at least minimize the aforementioned inconveniences, the present invention provides a propulsion unit for a vehicle including a dynamotor, which is driven by electrical energy and has generator functions and is directly connected to an engine driven by combustion of fuel. The dynamotor is composed of the motor rotor and the motor stator disposed for correspondence to the motor rotor, and a rotational displacement detection mechanism is provided which is composed of the sensor rotor, which detects rotational displacement of the motor rotor relative to the motor stator, and the sensor stator disposed for correspondence to the sensor rotor. A magnetic-proof member is provided between the dynamotor and the rotational displacement detection mechanism in order to shield the detection mechanism from magnetic flux and radio wave noise which leak or are emitted from the dynamotor.
Pursuant to the present invention, because the rotational displacement detection mechanism is shielded from the magnetic flux and the radio wave noise which leak from the dynamotor, noise in the rotational displacement detection mechanism is avoided or at least minimized. The noise occurring in the signal of the rotational displacement detection mechanism is thus reduced.